This invention relates to a device and method for absorption, retention, and biomediation of hydrocarbons to avoid pollution especially such as may result from marine oil and fuel spills.
In addition to booms for controlling oil tanker spills and the like, there has long been a need for a bilge or sump oil absorber that combines the advantages of high absorbency and containment properties of melt blown polypropylene absorbents presently on the market with the bioremediation properties of systems containing bacteria that consume, over a period of time, accumulated hydrocarbons.
Polypropylene and similar absorbents have disadvantages in that they do not consume or remediate hydrocarbons but simply trap them and, as a result, must be disposed of as either hazardous waste or, in a case where they meet certain criteria may end up in a landfill where resulting pollution is passed from water to land.
Bioremediation products on the market which include a microbial component such as hydrocarbon neutralizing bacteria do degrade relatively small amounts of hydrocarbons but cannot handle large amounts as might result, for example, from a sudden release of fuel/oil into the bilge or sump of a boat. If exposed to large quantities of hydrocarbons the microbial materials are usually overwhelmed and killed.
Accordingly, it is an important object of the invention to provide a device for absorbing large quantities of hydrocarbons for controlled bioremediation over time.
Another object of the invention is to provide a bioremediating device and method wherein large amounts of hydrocarbons may be extracted as from an external spill and stored for breakdown in a controlled sequence over a period of time. After remediation has progressed within the device biologically active material may escape so as to further treat remaining external hydrocarbons thus further protecting the environment from hydrocarbon pollution.
The invention contemplates combining high absorbency characteristics of products like polypropylene to facilitate a timed release of bacteria specific to degrading hydrocarbons. Large external accumulations of hydrocarbons are absorbed by an outside matrix of polypropylene or cellulose which may contain nutrients and microbial organisms. The matrix primary function is to retain an accumulation of hydrocarbons and to wick them by capillary action into the core in juxtaposed relation therewith where a concentrated source of bacteria are released on a time controlled basis to consume the accumulation of absorbed hydrocarbons which over time are broken down to more benign material.
Highly absorptive forms of recycled cellulose have been found to be in the order of about 90% as efficient as melt blown polypropylene for absorbing hydrocarbons and would allow the entire device to biodegrade as in a landfill. The necessary components for operation of the device include water, oxygen, nutrients, bacteria or other suitable organisms and the hydrocarbons.
While the invention has been described in the context of a bilge or sump oil absorber many uses will be found for the device and method of the invention including controlling and bioremediating many larger spills and the like on land as well as water.